Somewhere I recall reading that Sony supposedly had longer better battery life. Ideas?

Not really. I've got both the Sony 500 and the Cybook Gen3. And I just can't turn pages as fast with my Sony as with the Cybook. Probably this is different with the 505 as it has - to my mind - a more logical button size and layout. Mom is more patient than I am so she doesn't mind the difficulty in using the 500's page-turn buttons.

However, as I tend to read fast, I *can* state that those page-flips go by real fast and I usually end up burning through the battery in about 5 ebook novels. (About 4 days.) Also remember that for those of us who need larger font sizes (Damn, 'old-age' eyesight is a pain!) equates to more page-flips per ebook and, thus, fewer ebooks per battery charge. I've found that in 100-Watt lighting, if I don't have my 'reading' glasses to hand, I have to up-size by two font sizes to read - which effectively turns a 1,200 epage book into a 2,100 epage book. Oops!

The Sony runs for about 3 weeks in "standby" mode compared with, I believe, about 3-4 days for the CyBook. Both, however, allow you to switch them fully "off" in which case they'll stop using power. In terms of actually "reading time" I'd expect them to be pretty similar.

I'll find out for sure on Monday when (hopefully) my Gen3 gets delivered

Some of the testing we (I mean MobileReaders, not me personally) did early on with the PRS500 found that not only was the battery life shortened by using a memory card instead of internal memory, but also that the amount of difference varied pretty widely with brand of memory card.

That is something I didn't think of. So to optimize battery life keep te books you want to read internal. Use the memory card only as the main library but not in the device. Only transfer them when you need them. Do you have any data on the brands that use less than others?

What I would really love to see is a Sony Reader with Mobipocket support.
Those 3-4 weeks of standby are something nobody has managed yet apart from Sony (and Jinke with some of the Hanlins) and it is a feature that I MUST have in any ereader device that I'd even consider spending money on.
Mobipocket is something that actually makes buying AND converting books so much easier and faster that it also is on my "must-have" list for any future device.

The Cybook is surely a nice device, but if they don't get it to do Sony-Reader battery life then I'd never consider it. I know the approx. 1 business week of Standby from the STAReBOOK...it's OK and much better than the Iliad, but it does not give the same kind of freedom a full month of charger-free life promises.
Of course, if the device had "instant-on" or at least a booting time <10 seconds I would not mind a lower Standby time that much, but as it stands the devices all take a while to get going after you turn them completely off and that makes it vitally important to me that you can leave it on 24/7 without fear of discovering that it ran out of juice just lying there doing nothing...

....Of course, if the device had "instant-on" or at least a booting time <10 seconds I would not mind a lower Standby time that much, but as it stands the devices all take a while to get going after you turn them completely off and that makes it vitally important to me that you can leave it on 24/7 without fear of discovering that it ran out of juice just lying there doing nothing...

If you set it to go really off after 30 minutes or so, you can lay it down for as long as you want. (weeks / months) the only thing is when you pick it up again, you'll have to wait 14 seconds to start up again.

"As you get in sleep mode between each page flip and the Cybook switches off automatically after a certain delay of inactivity, the Cybook battery lifetime can vary from several hours (MP3 playing) to several month (80 page flips per day with switch-off at the end of each reading session)."

What I would really love to see is a Sony Reader with Mobipocket support.
Those 3-4 weeks of standby are something nobody has managed yet apart from Sony (and Jinke with some of the Hanlins) and it is a feature that I MUST have in any ereader device that I'd even consider spending money on.
Mobipocket is something that actually makes buying AND converting books so much easier and faster that it also is on my "must-have" list for any future device.

The Cybook is surely a nice device, but if they don't get it to do Sony-Reader battery life then I'd never consider it. I know the approx. 1 business week of Standby from the STAReBOOK...it's OK and much better than the Iliad, but it does not give the same kind of freedom a full month of charger-free life promises.
Of course, if the device had "instant-on" or at least a booting time <10 seconds I would not mind a lower Standby time that much, but as it stands the devices all take a while to get going after you turn them completely off and that makes it vitally important to me that you can leave it on 24/7 without fear of discovering that it ran out of juice just lying there doing nothing...

You keep forgetting that I don't graze through my ebooks. I'm in a situation where I can read continuously for 8-12 hours per day. And I'm flipping pages fast enough to get through a 1,200 page (Georgia font, about 14pt) book inside of 10 hours. That's a hell of a lot of page flips per day! Now on the few occasions when I could restrain myself from reading, say by leaving the Cybook on overnight, the power drain was not measurable during that time.

So I'd say that an *average* reader, who leaves the Cybook on all the time, with spurts of reading between 30 minutes and 45 minutes at a stretch, maybe two-three hours per day, will probably see two weeks of battery life easy.

So what is the boot time for the Cybook? I notice that it is not mentioned on the web site...

You must remember there's no 'resume from sleep' mode similar to what the Sony offers. When the Cybook resumes, it comes up from a cold start - every time!!! Off is OFF!!! If the screen is *blank* the Cybook is OFF!

Thus, it does a full boot every single time and that means it takes a few seconds (I counted 18 seconds!) to get back to the Library upon start-up. That's right, unlike the Sony, when you're starting from a 'blank-screen' *off* state, it *always* boots to the Library! Now it's nice enough to position itself at the currently (last used) file, but you have to then re-enter the ebook.

However, given that the Cybook draws so little power when it's just *sitting* there, there's no real reason to not leave the power on and keep the ebook open if you're going to be not reading for a while.

Good to hear that the Cybook is improving in terms of Bettery Life. If it manages two weeks of "Standby" with Firmware 1.00 it might even be able to rival the Sony Reader sometime. I based my comparison on your statents from the original "mini-review" and on my own STAReBOOK experience.

A booting time of 18 seconds is quite OK, maybe some tweaking there could also still improve that. I remember that my STAReBOOK booted a lot faster than the Iliad, but I don't remember the exact time it took to go from full-off to library.
If you take the Cybook in it's 1.00 state and add the feature of "return to last-read book on bootup" that they Iliad now sports, then It's a lot closer to ideal in my opinion. The Sony Reader still leads in that field, but the advantage is getting smaller.
With two weeks of "always-on" battery life I could extend that to almost 4 weeks by switching the device off over night.
It's almost a pity that I'm waiting for the Kindle...

UPDATE: I just timed the booting time of the STAReBOOK and it seems to be almost exactly 18 seconds...^^